The best test is a radio with a known good or new accessory jack. Cords to earpieces and other audio accessories are the common failure part of the device. They can be damaged at the grommet (near the plugs) by users who repeatedly plug and unplug them. The wiggling side-to-side motion can break solders and wire connections. Also some users will twirl the earpiece on the wire when not in use, a bad nervous habit which can break the wire in the cord. Earpiece are not considered repairable, and simply need replaced when they fail.
The other thing you could be having trouble with is the audio accessory jack on the radio. This can be damaged by repeated use, and can get wobbled out over time. Each seems to have their own "sweet spot", sometimes simply swapping earpieces with another radio will make a previously failed device work great.
On the CP200 radio it is strongly advised to use the optional audio accessory retain to hold any plug in place. Then you can leave your device plugged in and save wear-n-tear on the jack.
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The best test is a radio with a known good or new accessory jack. Cords to earpieces and other audio accessories are the common failure part of the device. They can be damaged at the grommet (near the plugs) by users who repeatedly plug and unplug them. The wiggling side-to-side motion can break solders and wire connections. Also some users will twirl the earpiece on the wire when not in use, a bad nervous habit which can break the wire in the cord. Earpiece are not considered repairable, and simply need replaced when they fail.
The other thing you could be having trouble with is the audio accessory jack on the radio. This can be damaged by repeated use, and can get wobbled out over time. Each seems to have their own "sweet spot", sometimes simply swapping earpieces with another radio will make a previously failed device work great.
On the CP200 radio it is strongly advised to use the optional audio accessory retain to hold any plug in place. Then you can leave your device plugged in and save wear-n-tear on the jack.
Best regards